1. Field of the Invention
The present invention relates to a program information broadcasting system for broadcasting information of component elements to constitute a program such as category information, performer information, etc. of each of the programs to be broadcast, and further to a broadcasting device used for the above broadcasting system, and to a receiving terminal unit for receiving various types of program information thus broadcast and for displaying the information quickly and efficiently.
2. Description of the Prior Art
In recent years, with development and progress of communication technique and data processing technique, multimedia information such as audio information or video information is digitalized and offered to users. Also, with the introduction of large capacity storage medium in the market, it is now possible to provide a broadcasting system, which can send a large amount of data via broadcasting or communication facilities, and receive and accumulate the information at a terminal unit on user side so that the users can view it at any time desired.
Normally, in case a viewer receives and views a broadcasting program using a receiving terminal unit such as television receiver or radio receiver, the user is informed of program content and broadcasting schedule on program schedule in television/radio page of newspapers or magazines and decides the program to view or listen. When the user wants to subscribe a program, it is necessary to input and set broadcasting channel, scheduled broadcasting time, etc. of the program found on newspapers or magazines. In this respect, when the user does not have newspaper or magazine at hand, program subscription cannot be inputted because no program schedule can be referred.
Under such circumstances, it is now partially practiced, in case of television broadcasting, for example, to use a new type of television receiver provided with a data decoder, by which program information including program title and other information is broadcast in multiplex on video signal via teletext or the like, and program schedule can be displayed on screen of the television receiver. As an example, in digital satellite broadcasting, which has been recently started in Japan, program information and broadcasting program are broadcast.
In the broadcasting of program information as proposed in the past, broadcasting center prepares and transmits a program information (master data) and transmits the program information in broadcasting, and the data of the broadcast program information is received and reproduced (or decoded) and displayed on display unit. Included in the program information related to each program are program identification number, program title, broadcasting channel, explanation of program content, program category, individual key word relating to the program (data items such as performer, director, original author, etc.; generally called “items”), date and time of broadcast starting, date and time of completion of broadcasting, etc.
In the digital satellite broadcasting, the program information is transmitted at the same time as the broadcasting program. By receiving the program information, electronic program guide (also called “EPG”) is prepared, and program information is displayed to the users. Using the electronic program guide, the user can obtain various types of information relating to the program on television screen in the same manner as the checking of program on newspaper or other media. Also, it is possible to subscribe or purchase the program using the electronic program guide. The electronic program guide is practically used in the digital satellite broadcasting, which is currently in the stage of practical application. in case program information is retrieved on the electronic program guide as described above, the data of the program information is received by a receiving terminal unit, stored in memory of the receiving terminal unit for once, and is displayed on display screen after retrieval.
However, in the broadcasting of program information as proposed in the past, data is retrieved only after all of the data to be retrieved is incorporated in memory or retrieval of the data is conducted while incorporating the data. In any case, the retrieval cannot be completed until all of the program information is completely incorporated, and the user must wait for relatively long time until program information is actually displayed after an instruction to display the program information is inputted.